The present invention relates to a method and system for treating organically contaminated waste water for reuse. The invention is particularly useful in waste water treating systems wherein the space available for such a treatment system is limited and/or where the concentration of the organic contaminants is relatively high.
Many systems are known, and are in present use, for treating organically contaminated waste water in order to permit reuse of the waste water, e.g. for agricultural purposes or the like. One known system includes a sedimentation tank for receiving the waste water and for removing a significant portion of the organic contaminants; an anoxic mixing chamber for denitrifying the waste water; and a rotary biological contactor for nitrifying the waste water by aeration, and for assimilating organic materials therein by bringing the waste water into contact with a biological medium. The so-treated waste water may then be conducted to a clarifier, chlorinator, filter, or the like to further purify the water.
The known systems of the type including rotary biological contactors generally require considerable space and/or residence time, to treat the waste water sufficiently to permit its reuse when an advanced denitrification process is required, e.g. for irrigation purposes, and are therefore not suitable for the onsite treatment of waste water in residential and small commercial applications in hydraulic sensitive areas.